Johnson Controls METASYS VAV110 Technical Manual page 44

Sharing a Sensor
1 2 3 4 5 6
O
N
1 2 3 4 5 6
O
N
44 VAV Controller—Variable Air Volume Controller
You may use one sensor as a master input to multiple VAV Controllers
instead of mounting and wiring separate zone sensors for each controller.
This application is especially beneficial when you have a mechanical
system that uses more than one terminal unit to serve the same area, for
example, a large conference room or open office space.
Note: The practical limitation to this application is four VAV Controllers
to one sensor.
Set for
2 VDC and
Voltage
T M
ANALOG INPUTS BINARY INPUT BINARY OUTPUT
TO
1 2 3 4 5 6 1 2 3 4 1 2 3 4 5
ZONE
STAT
Z BUS
1 2 3 4 5 6
ANALOG INPUTS 24 VAC
COM M ON
1 2 3 4 5 6
ANALOG INPUTS BINARY IN BINARY OUTPUTS
DSI
P 5 P6
Sensor +
Sensor -
Note: Route sensor wiring and N2 wiring together. Since the VAV Controller is a self-terminating
device, end-of-line termination for the N2 Bus is not required.
Figure 18: Example of Sharing a Sensor Among VAV Controllers
Figure 18 shows the wiring and analog input switch settings for
two controllers that use one zone sensor. To ensure the noise immunity of
the VAV Controllers, pull the N2 Bus wiring with the sensor wiring
between controllers that share the same zone sensor.
Notes: This configuration shifts the AI value by one degree for each added
controller. Compensate for this temperature shift by entering an
offset of -1°F (for each added controller) through the AI Offset
Table. You can find this table in the Commissioning mode of
HVAC PRO for Windows.
On the HVAC PRO for Windows Analog Input Modify screen,
verify that both controllers are set to the same temperature sensor
type.
If the master zone sensor uses the Zone Bus connection, only the
master controller can be loaded and commissioned from the sensor
connection.
1 2 3 4 5 6
O
N
1 2 3 4 5 6
O
N
6 7 8
1 2 3 4 5 6
1 2 3 4 5 6
ANALOG INPUTS
N2 -
N2 +
N2 REF
Set for
2 VDC and
Temperature
T M
ANALOG INPUTS BINARY INPUT BINARY OUTPUT
TO
1 2 3 4 5 6 1 2 3 4 1 2 3 4 5 6 7 8
ZONE
STAT
Z BUS
ANALOG INPUTS 24 VAC
COM M ON
BINARY IN BINARY OUTPUTS
DSI
P 5 P6
Metastat
8-pin Connection
on Back
sensors2